The present invention relates to the physical packaging of electronic circuits and similar items, and more particularly concerns a system for mounting multiple subassemblies at high density on a single base card.
Electronic and optoelectronic circuits seem to decrease in physical size almost without limit. This usually does not result in a decrease in the size of the overall system, but rather the inclusion of ever increasing numbers of circuits within a single system. In many systems, such as switching systems, communications systems, and the like, the demand is to package larger numbers of a common subassembly within the same frame. For example, a system for interconnecting multiple optical fibers may require dozens of "link cards" which each convert a serial optical signal at gigabit frequencies into a parallel electrical signal and vice versa. In such systems, the high signal frequencies also make small physical size and dense packaging very desirable.
Previous advances in electronics packaging at the card or subassembly level have required large spacing between adjacent subassemblies for insertion and removal, have been difficult to insert and remove, have been fragile or expensive, or have interfered with heat dissipation from the system.